Idle W/NG

Singles, twins and fours.
User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3561
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Idle W/NG

Postby simon.holyfield » Thu Aug 08, 2019 7:34 pm

I've just finished looking at the timing. I have the spark at tdc on full retard, somewhere near 5/8" btdc on full advance.
I found two things, one relevant, one not. The points gap had closed to a few thou, which by rough maths would equate to maybe 15 degrees extra retard; secondly my mag chain is due for replacement.

Starting it just now, it seems to be much better. Road test tomorrow.
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

pete.collings
Holder of a Waxed Cotton Anorak
Holder of a Waxed Cotton Anorak
Posts: 553
Joined: Fri Feb 18, 2011 10:26 am
Location: Cardiff
Contact:

Re: Idle W/NG

Postby pete.collings » Thu Aug 08, 2019 7:45 pm

Should be a test for your wet weather gear as well as the bike ??

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3561
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Idle W/NG

Postby simon.holyfield » Thu Aug 08, 2019 7:59 pm

Is that right? I haven't looked at the weather yet.

Maybe it will give me a chance to stop this riding lark and finish the FH mudguard!
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

Brian Petheram
Posts: 53
Joined: Mon Apr 29, 2019 4:17 pm
Contact:

Re: Idle W/NG

Postby Brian Petheram » Fri Aug 09, 2019 9:00 am

A few of the shorter carb nuts have just appeared on Ebay - this is NOS but he also has used ones a bit cheaper if you view his other items:
https://www.ebay.co.uk/itm/amal-274-275 ... SwVQNdHcu6

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3561
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Idle W/NG

Postby simon.holyfield » Fri Aug 09, 2019 1:46 pm

Hmm, still not idling happily. I have fuel in the pilot passage when I tickle.

Not sure if I should have a short or long nut?
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3561
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Idle W/NG

Postby simon.holyfield » Fri Aug 09, 2019 2:03 pm

Looking at the Amal book, it looks like there are two jet block nuts listed for the 276 (6/062 and 6/033), but only one for the 275 (4/062).

I guess I must have the right one.
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

User avatar
alan.moore
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 1280
Joined: Sat Jul 19, 2014 1:29 pm
Location: Leicestershire UK
Contact:

Re: Idle W/NG

Postby alan.moore » Fri Aug 09, 2019 4:25 pm

Simon, have you checked the fuel level as suggested, this will tell you if the jet block nuts is correct and also the fuel level which, if wrong, will effect the idle.
1939 VH Redhunter;1942 RN WNG;1951 Triumph 6T Thunderbird;1970 BSA B175 Bantam;1986 Yamaha SRX600 single
http://cloggymoore.wix.com/triumph-pre-unit-6t

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3561
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Idle W/NG

Postby simon.holyfield » Fri Aug 09, 2019 4:47 pm

alan.moore wrote:Simon, have you checked the fuel level as suggested, this will tell you if the jet block nuts is correct and also the fuel level which, if wrong, will effect the idle.


To a point yes, but I have not had time to make a fitting to go onto the drain port - do you happen to know what thread it is? I might make some sort of tapered plastic cone or something to take a bit of clear tube.

I've had a look through the inlet, down toward the needle jet - I can just see fuel there, but I suspect the fact that I cannot see fuel easily suggests it's low. It floods as normal, out of the overflow and out of the pilot passage.

I have it apart at the moment - I wanted to have a look at the pilot screw seat to make sure it is not mangled - the passages are all clear, but the pilot air screw does not seem to make any difference to the idle.

I'll get there.
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'78 CX500
http://ariel-square-four.blogspot.com

User avatar
alan.moore
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 1280
Joined: Sat Jul 19, 2014 1:29 pm
Location: Leicestershire UK
Contact:

Re: Idle W/NG

Postby alan.moore » Fri Aug 09, 2019 4:55 pm

I used a spare drain port screw and drilled a hole through it and soldered in a length of brass pipe.

How does the height of your jet block nut compare with mine?

Re your throttle stop screw being all the way in I have mearsured mine at 0.950 (base of threads to the end) so if yours is the same length it must be lifting the slide up more then is normal, maybe this is connected with your issue? Maybe the carb is running on the needle jet rather than the idle circuit which is why the pilot air screw does not do anything

Cheers
Alan
1939 VH Redhunter;1942 RN WNG;1951 Triumph 6T Thunderbird;1970 BSA B175 Bantam;1986 Yamaha SRX600 single
http://cloggymoore.wix.com/triumph-pre-unit-6t

User avatar
alan.moore
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 1280
Joined: Sat Jul 19, 2014 1:29 pm
Location: Leicestershire UK
Contact:

Re: Idle W/NG

Postby alan.moore » Fri Aug 09, 2019 5:00 pm

You've probably read all this but Hitchcocks have some great info re the premonobloc carb here

http://accessories.hitchcocksmotorcycle ... e-Monobloc
1939 VH Redhunter;1942 RN WNG;1951 Triumph 6T Thunderbird;1970 BSA B175 Bantam;1986 Yamaha SRX600 single
http://cloggymoore.wix.com/triumph-pre-unit-6t


Return to “Four stroke”

Who is online

Users browsing this forum: No registered users and 7 guests